When light is shown in one eye then immediatly moved to the other eye, the consensual response is seen in the second eye, then the direct response catches up. At this point the difference can be detected. In APD consensual response > direct response

Pinhole testing

* What the patient's vision would be like with glasses. used to overcome refractive error, if the pt doesnt have their glasses with them or their rx is out of date. Test the pt with a tiny hole punched in a sheet of paper.